The Washington Post Co. announced Tuesday that it has agreed to purchase online magazine Slate from Microsoft.

In a deal that had been rumored since at least mid-November, the Post will take Slate off Microsoft's hands for an unspecified amount of money. The online magazine, which produces original editorial content on popular topics such as politics, has been controlled by the software giant since Slate first began publishing in 1996. According to Nielsen Net/Ratings, the magazine had 6 million unique users in November.